Androxus is great at short distance but he also can do much from long distance. The best way to counter him is bait him to use Reversal unnecessarily and force him to waste all Nether Steps and just stay grouped up.
Unless your Champion's basic attack is hitscan, like Viktor or Tyra, you'll be hard-pressed to hit Androxus while he's airborne. Wait for him to land, if you can.
Good aim will take you a long way on this champion. Learn his range. Always have an escape plan. Understand how to win every matchup (will come with time). Use your mobility!